Re: [Mingw-users] Display a stacktrace when an exception occurs

[K. F. <kfr...@gm...>]

Hello TSalm!

On Sun, May 1, 2011 at 5:12 PM, TSalm <TS...@fr...> wrote:
> Le 01/05/2011 00:26, K. Frank a écrit :
>> Hi TSalm!
>>
>> On Sat, Apr 30, 2011 at 5:55 PM, TSalm<TS...@fr...>  wrote:
>>> Hi,
>>>
>>> Is there away to catch an exception and display his stacktrace ?
>> I believe that the answer is no, if I understand your question.
>>
>> Ordinary, built-in c++ exceptions do not take a snapshot of the
>> stack or build a stacktrace as they unwind the stack.  This is
>> by design, as c++ doesn't want to impose on you the cost of
>> building and maintaining this stacktrace.
>> ...
>> When I'm doing development and debugging, I generally put in assets.
>> These cause the program to core dump (or send control back to the
>> debugger) right at the point where the error is detected (i.e., the assert
>> fails), and then you can look at the state of the stack when the error
>> occurred (unless your bug has corrupted the stack...).
>
> I understand. On an other side, why the -g switch doesn't insert
> something to manage this stacktrace when an exception occurs ?

I don't know the answer as to why -g doesn't add this functionality.
Ultimately it's some design decision.

But your suggestion sounds like a good one to me.  You could argue
that once you use -g, you're not asking for best performance, and
you are asking for help debugging things.  It seems reasonable for
-g to say you're going to take the significant performance hit of having
the exception stack unwinding build a stack backtrace as it goes,
and report it to the debugger or a core dump should the exception
not be handled.  (Of course, this would represent new functionality,
and considerable effort for the compiler developers.)

A feature like this certainly would have saved me significant time
and effort debugging in certain situations.

> Thanks.

Good luck.


K. Frank